


2B, 2B, LKD

by vipjuly



Category: Supernatural
Genre: Alternate Universe - College/University, First Time, Frottage, M/M, Med Student Castiel (Supernatural), Murder Husbands, Past Michael/Dean Winchester, Serial Killer Castiel (Supernatural)
Language: English
Status: Completed
Published: 2020-11-12
Updated: 2020-11-12
Packaged: 2021-03-09 17:46:42
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 4,453
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27520228
Author URL: https://archiveofourown.org/users/vipjuly/pseuds/vipjuly
Summary: If one is to move through the ceaseless monotony of the world with splashes of crimson, one should always have an alibi ready.Castiel puts out an ad for a roommate.[A/N: check the end notes at the end of the story for a surprise!]
Relationships: Castiel/Dean Winchester
Comments: 65
Kudos: 311





	1. Chapter 1

**Author's Note:**

> me: i'm done writing destiel i hate everything  
> also me: just....maybe one more

**Wanted:  
One roommate.  
Gender unimportant.  
Ages 25-35.  
Must either have a full time job or be in university, or both.   
No pets. No smoking.  
Two bedroom, two bath apartment with communal kitchen, living and dining.  
All bills split in half.**

\--

The evening is quiet, enough cloud cover over the full moon to ensure no shadows are cast through the trees and along the frozen ground. Owls hoot, crickets chirp, various critters disturb the underbrush as they go to and fro. There’s an artificial sound scooting across the ground, displacing leaves with a _shhhh-shk-shk_. A lone figure hauls a tied off tarp, nary a sweat breaking on his brow as he drags the heavy load through the woods. He’s strong, broad shoulders with an equally broad chest, wearing a plain t-shirt and jeans on thick legs as he makes his way into the darkness. His dark hair obscures his face, but the glint of his white teeth reflects over the ambient light of the night. 

A trip to the grocery store had gotten out of hand when a middle-aged woman decided to accost the teenage cashier.

Naturally, Castiel had decided to take care of that little problem. 

That problem being the… _Karen_ currently decomposing in the tarp at a delayed pace thanks to the frosty air. Castiel doesn't really think himself a vigilante, as he generally had no rhyme or reason as to how he chose to express his… more creative self, but it was always nice when victims put a target on their back and practically screamed “KILL ME!”. 

It occurs to him, as he starts filling up the grave he’d tossed the tarp in, that while he’d put an ad in the papers for a roommate to help with finances (really, he could handle all the bills himself, but he was saving up for a house and therefore had to pinch some pennies in this godforsaken after-boomer market), there could be another… _more_ useful purpose to having someone at home, knowing his comings and goings. 

Not that he wasn’t careful. Not that he thoughts the cops could attribute _any_ of his crimes to him. 

But… the safety net would be nice. 

He grunted, wiping the sweat from his brow as he stared at the half-full hole.

Television shows made this look way easier.

\--

_One week later…_

Breakfast.

Arguably, the most important meal of the day.

Castiel wakes up every morning at promptly six a.m.; showering takes fifteen minutes, dressing another ten, and depending on what he decides to prepare for breakfast, he’s seated at the small, two-person table in the kitchen by seven-thirty to enjoy his meal. It was important to keep a schedule--not only for his neurotic personality, but also for his new roommate to keep tabs on him. 

At seven thirty-five his roommate, one Dean Winchester, blows through the kitchen in a whirlwind of “shit shit shit”s, improperly buttoned shirts and untied shoes. Late for class, as usual. 

Every morning, Castiel closes his eyes to count backwards from one hundred. 

When he reaches fifty, Dean is gone, a deafening silence left in his wake.

Castiel will look down at the breakfast spread--be it pancakes, hash, or even just cereal--to see that Dean has taken a portion to go. 

Every morning, Castiel will clench his fork so tightly it threatens to bend. 

Every morning Castiel swears Dean will be dead by the end of the day, usefulness or not.

\--

There are few material things Castiel is thankful for, but when his phone pings and sends the ring to his airpods while his hands are full, he counts his stars. 

He uses his shoulder to press the button to answer.

“What.”

“Heya!” Dean’s cheery voice bounces around his skull. “You gonna be home soon? Dinner’s almost ready.”

The person in Castiel’s trunk lets out a terrified noise behind the duct tape, clearly understanding that Castiel had taken a phone call, making some sorry attempt to attract attention. Castiel grabs the man by his hair, using his powerful arm to smack his head against the floor of the trunk to daze him. 

“Yes,” Castiel replies, not a hair or breath out of place. “I was returning a book to the library.”

“You know you can just uh… _buy_ books, right?” Dean asks, amused. Castiel, after a period of adjustment, has grown fond of Dean’s easy attitude. If “fond” was an actual emotion he could be capable of. He’s not sure, yet.

“Our apartment is too small for proper shelving for how many books I wish to own,” he replies. The man in the trunk’s eyes flutter open, looking up at Castiel with a resigned, pitiful tilt. 

“I can build ya some,” Dean offers, because he’s handy and kind. 

The bound and gagged man weakly tries to kick at Castiel. Castiel’s big, strong hand snaps out to grab his ankle, breaking it with one mighty, expert twist. A tortured scream gets caught behind the duct tape, Castiel leaning bodily away from his car so the sound doesn’t carry to Dean on the other end of the line. 

“I appreciate the offer, but seeing as how an apartment is temporary until I can buy a house, I’d rather not customize it too much.” 

He shuts the trunk with a slam. Dean doesn’t comment on it, but instead says, “You painted the living room.”

“If you’d seen the color on the walls beforehand, you would have told me to,” Castiel says with a small smirk. 

“Fair enough,” Dean laughs. “Anyway, dinner’s gonna get cold!”

“I’ll be home shortly.” 

“Don’t scare that nice librarian.” 

Castiel sends his car an amused glance as he walks away from it, a shovel slung over his shoulders as he goes deeper into the woods. “I haven’t scared anyone today.” 

Dean’s melodious laugh carries him through to the desired spot, before he disconnects the call. 

Roommates are the perfect alibi.

\--

If necessary, Dean could confirm that he and Castiel were home all night.

If necessary, Dean could confirm that Castiel had been running errands.

If necessary, for any reason whatsoever, Dean would be able to corroborate anything Castiel may need to tell anyone at any given time. 

They lived _just_ separate enough from one another that Dean would, if put under pressure, likely default to “he was in his room all night”, because as far as he knows, that’s where Castiel spends all of his “grumpy study time”. 

It’s perfect.

Dean is perfect.

\--

Sometimes, Castiel is sure he could kill Dean. Add him to his list. Bury him six feet under. Dismember him limb by limb, digit by digit. Disembowel him while he watches, make him hold his own intestines in his hands while Castiel reads the encyclopedia out loud so he could, in all essence, bore him to death. 

Dean’s annoying. He’s loud. 

He’s, Castiel slowly realizes, beautiful. 

And that pisses Castiel off, naturally. 

He’s never thought someone beautiful before. 

Not until now. 

He should just kill him to get those distractions out of his head. 

Instead… he lets Dean live. 

Because Dean is beautiful, and Castiel has never known beauty. 

\--

Clenching his jaw to prevent himself from grinding his teeth together, Castiel listens as Dean and Michael have their fifth argument of the night. It’s always small and inconsequential, the things they fight about, and it’s more Michael picking on Dean than Dean actually doing anything wrong. The man is brash and loud and jokes about weird things, but he’s sweet at his core, loyal and beautiful. Even Castiel can see that. 

He’s been shut up in his room studying since Dean announced that Michael would be coming over. He doesn’t like Michael. He doesn’t like his slick hair and icy eyes and his peacocking. He especially doesn’t like how he treats Dean. Castiel doesn’t think he’s _fond_ of anyone, let alone a man that can be as annoying as Dean Winchester, but his roommate does have a special place in the hole where his heart used to be. Maybe _that’s_ what fondness is? Clueless and gullible, Dean is exactly who Castiel needs in his life to appear… normal, and to not raise suspicions. 

The arguing ceases suddenly, a crack resounding. Castiel doesn’t flinch as he stands up immediately, throwing the door to his bedroom open so he can stand in the doorway and stare Michael down like a wolf to a rabbit. Dean has his hand up on his reddening cheek, green eyes bright, lips parted in surprise. 

Michael’s gaze cuts toward Castiel. “The fuck are you looking at?” 

“I must ask you to leave,” Castiel says politely, though his voice is a growl. For a man who avoids eye contact with the common person, it’s easy to pin Michael to the spot with his glare. 

Michael, though, seems unaffected. “Like I’d stay for this slut.” 

The room shrinks in size with how fast Castiel’s legs carry him across it. He gets in Michael’s space, their chests and noses nearly touching, Castiel’s voice a low, nearly inaudible growl. “You will leave our home. You will never touch Dean again. You will never contact him, look at him, you will never breathe the same air as him again.” 

It’s impressive, really, the way Michael raises a brow at Castiel. “Is that so?” 

“Cas,” Dean reaches out to grab Castiel’s wrist. Castiel can’t remember if they’ve ever physically touched, but his fingers burn and lick fire up his forearm. 

“I dare you to go against my wishes,” Castiel says. 

A flicker of uncertainty passes through Michael’s eyes, and then he’s snorting and pulling away. “Fine. He’s not worth the trouble, anyway.” 

Michael leaves. 

Dean still holds Castiel’s wrist. 

Smoothing his shirt down, Castiel dislodges his wrist and turns to face Dean. “Please let me know if he causes you trouble in the future.” 

Looking mildly flustered, Dean nods. 

Castiel returns to his room. 

Annoyed.

He’s stumped, constantly, by the basic human desire to share romantic, sexual company with someone. 

Seems more trouble than it’s worth. 

But, he reasons, Dean is beautiful, so he can see why someone would attempt that with him. 

Certainly not him, though.

\--

“Game Nights” are ridiculous. Castiel doesn’t even hide his displeasure at their apartment turning into a zoo when Dean’s friends and brother come over. Food, games, the television _and_ radio on, alcohol. 

Of course Castiel stays sober. 

Dean looks at him under his lashes, teases him a bit more than usual, and while Castiel is emotionally inept, he’s not stupid. 

His roommate is attracted to him. Especially now, Castiel surmises, that he’d thrown Michael out of their apartment. As far as he knows, Dean hasn’t talked to Michael since. Good riddance.

He excuses himself halfway through under the guise of getting more alcohol. Nobody at present needs more, but the bottles are empty, and he needs an excuse to leave the noisy apartment. A man cuts ahead of him in line at the liquor store, shooting Castiel a snooty look and putting some large bills on the counter for “the good stuff”. 

Ah. Just what he needs to take the edge off.

Castiel follows him to his car, knocks him out with a bottle of Jack’s, then drives him to the edge of town to dismember him and leave him in an alleyway with half a bottle of vodka perched prettily in his exposed brain.

Without a speck of blood on him Castiel returns to the apartment, brandishing bags of alcohol. 

His mood is _much_ better, now. He’s even _smiling_.

Dean hangs on him like a barnacle, hooting out, “Our savior!”

Physical contact is… kind of nice.

\--

Dean’s table manners are atrocious. He flies by Castiel in the mornings, takes some food “to go”, and there are _so many times_ Castiel considers just killing him. Just getting rid of him. Having a roommate to solidify alibis is only important if the cops come sniffing around, but they haven’t, and they won’t, so what’s the point of Dean? 

Well- Castiel supposes his smile is nice.

And his easy, ceaseless friendship is also… not terrible. 

He respects Castiel’s privacy and indulges in his company when he’s allowed, even if he knows Dean has a… crush on him.

Honestly, if Castiel had run into Dean on the streets, he wouldn’t have thought twice about him. Dean’s manners are occasionally awful but he has a good heart, is pure at his core, and Castiel can see that about him. Castiel doesn’t hurt nice people. 

Though he imagines strangling Dean until he’s on the brink would be pretty satisfying. 

His cock leaps whenever he has those images. Strange.

He tries to not think of it often, but Dean is just _Dean_ and he often incites these urges within Castiel. 

It’s vexing.

\--

“Sometimes you worry me,” Dean laughs from across the table. “Like you’re a serial killer or something.”

Castiel’s shoulders tense without his permission as he cuts into the pie Dean had so lovingly baked. He doesn’t look Dean in the face as he takes a slow, careful bite, savoring the flaky crust and the way the berries explode with flavor over his palate. He’s gone this long undetected. Dean doesn’t come off as Einstein, but he’s not an idiot. He’s also the only person in the entire world that spends so much time with Castiel one-on-one. It's only a matter of time until he figures _something_ out.

“Ha…” Dean’s laughter trails off. 

Still, Castiel says nothing. He lifts his gaze to Dean, who has a thoughtful expression over his features, brows furrowed slightly, green eyes glassy as they look over Castiel. 

They finish their dessert in silence.

Castiel changes his mind about killing Dean.

\--

Michael’s face is on the news a week later. Missing, possibly abducted after work. Castiel turns the page in his book.

Dean lets out a curious hum. "Michael's been texting me every day this week."

Castiel changes his mind about killing Dean, and comes up with a different plan instead.


	2. Chapter 2

“Are you fucking _crazy_!?” Dean shouts. He can’t open his door fast enough, fingers scrabbling over the interior of the door before finally hooking on the handle. It slips out of his grip three times, thudding dully against the well before he finally gets a solid enough grip to open the door and shove it open simultaneously. He can barely stand, his feet feeling like cement as he tries to distance himself from the car. 

Castiel exits the vehicle much more calmly. He puts the car in park, turns off the engine, then opens the back door to rummage around in the back seat. Dean should run. He should _sprint_. The highway is about three miles from this remote spot in the woods, he could make it. Cardio wasn’t his thing in high school but right now he feels like he could run halfway across the world with the way his blood is rushing through his body. 

The trunk opens. Michael lies in it, gagged and bound, a plastic tarp spread under him to prevent… anything… from staining the carpet lining. Castiel hadn’t scared him in their living room but now he looks absolutely terrified. Not a bit of hair is out of place, there aren’t any visible marks on his body. Dean thinks that he must have been drugged in order to be subdued and thrown into a trunk without incident. 

“Dean,” Castiel says softly.

Dean whips his gaze to Castiel. So does Michael. 

“You’re fucking crazy,” Dean whispers, pulse rabbiting in his throat. 

Castiel nods toward Michael, “Am I? This… _man_ threatened you in our home. Treated you like garbage. Had the gall to think he could get away with it. Then he wouldn’t stop calling your phone this week. Am _I_ crazy?” Blue eyes cut to Dean, stealing his breath. “Or is _he_ , for thinking that he could pass as a polite member of society?”

“A polite-” Dean lets out a hysterical laugh. Now that Castiel mentions it, he is probably the most polite fucking person Dean has ever met. Courteous, even. Oh, fuck. If you wanted to compare the two, Michael was the monster and Castiel was the saint. “What are you lookin’ to accomplish here, man?” 

Castiel gestures vaguely to the occupied trunk. “To kill him.” 

Dean feels like his eyes can’t get any more wide without falling out. “To kill him.” 

Like it’s obvious.

“You can either help or you can watch,” Castiel says, pushing the lid of the trunk open wider. Michael visibly flinches when the man gets near him. “Or, you could run back to the highway, flag down a car, call the cops--I’ve scrambled your phone, by the way--and turn me in.” 

“What the fuck kind of options are those?” Dean demands. He knows immediately that he should be terrified of Castiel, but he really only finds himself grievously exasperated. For the few months they’ve been living together Castiel has been the ideal roommate; clean, quiet, polite. Hell, the dude even cooks sometimes when Dean doesn’t want to. They’re not best friends by any stretch, Dean has kinda always thought that Castiel has some sort of social disorder, but- _this_?

“They’re the only options you have,” Castiel says dryly. His gloved hands reach to grab Michael by the collar, hauling him out of the car. Michael’s still wearing his work clothes, and Dean has no idea where Castiel has kept him til’ now, but he’s not dirty and smells… well, like Michael. Like expensive aftershave and freshly roasted coffee. He’s only been missing for three days. 

“Where did you keep him?” Dean asks before he can think. His brain is firing in too many directions all at once. He doesn’t know if he’s scared or thrilled.

“I have a furnished storage unit,” Castiel replies easily. Michael falls to the ground with a thud, though how strongly Castiel holds him is… damn. His arms look good. Michael easily weighs one-ninety, and Castiel’s just hauling him around like a fat watermelon. 

“What-” Dean licks his lips. Michael meets his gaze, frightened like a deer, and Dean rips his eyes away, afraid to let the situation wholly sink in. 

Afraid to learn that he’s having the entirely wrong reaction to learning his roommate is _actually_ a serial killer.

“I brought you along, Dean, with the intentions of letting you lead.” 

Now Dean feels panic rethread its way through his veins. Panic? Or… excitement? “ _Me_?” 

Castiel gestures idly, carelessly to Michael. “He was terrible to you. I’m giving you the opportunity to be terrible to him.” 

“That’s not- Jesus, Cas, that’s now how this works!” 

“Why not?” Castiel arches a cool brow. Still cool, calm, collected. Still the nerdy med student that keeps odd hours and drinks too much coffee and pretends he didn’t mean to make enough breakfast for two. 

“Because that’s not how you treat people, man,” Dean tries uselessly. As soon as the words are out, they feel like a lie. They feel like words spoken by someone else, physical on the wind--Dean can see them, read them, but they look like a foreign language, like something he can’t wrap his head around. 

“If you will not participate, I’ll have to kill you, too.” 

This time Dean’s heart stops in his chest. It’s glued to his ribs, which have also stopped expanding, his lungs filled with air and frozen on the exhale. His organs feel uncomfortable in his body. He can’t even sweat. He can’t even process the possibility of dying here tonight. 

“I don’t wanna kill someone just to save my life,” he says. 

“You save your life, Dean,” Castiel says, reaching into the trunk. He pulls out an intimidating-looking sheath, the handle of a huge hunting knife sticking out of it prettily, “not because I’m threatening yours, but because _he_ has, many times.” 

“That’s…” Dean’s voice comes out weak. He looks at the presented knife, how it doesn’t seem so big and scary in Castiel’s hand. 

“I’m not your enemy,” Castiel says softly. His eyes, big and blue and usually so guarded have a sliver of truth in them in this moment, as they regard Dean. It looks a lot like vulnerability. But it’s gone between one blink and the next, Castiel’s black-and-white mask slotting back into place. “I… care for you, Dean.” 

The hysterical laugh that bubbles up from the pit of Dean’s belly is unstoppable. He lifts his hands, covering his mouth, feeling his eyes water in a mixture of anxiety and disbelief. “ _Do_ you?” 

Impatiently, Castiel wiggles the knife in his direction. “I know I don’t _want_ to kill you. That alone tells me I care for you in some capacity.”

“You’re the worst med student ever,” Dean grumbles, feeling hysteria transform into twisted amusement. 

The smirk Castiel gives is icy hot. “I study the body. Not the mind.”

Dean takes the knife. He’d be lying if he said he’d never thought about physically hurting Michael. He’d been slapped around so many times but never felt the inclination to return the blows. It had all eventually built up to that final night when Castiel kicked Michael out of their apartment and after that… the anxiety had lessened, but the weight had gotten heavier. How could someone like Michael just make their way through life expecting the world to be handed to them on a platter? How can he just treat people like shit and expect goodness in return? How could he treat Dean like that, not only in private but in front of God knows who? How--

“Dean.” 

Dean snaps his gaze to Castiel. Castiel nods to the knife in his hand, where his fingers tremble to hold the hilt. 

“Stop thinking.” 

Inhaling slowly through his nose, he then exhales through his mouth. 

Castiel’s voice is a balm over his frenzied thoughts.

“Start _feeling_.” 

When it’s all said and done, Dean doesn’t actually remember _killing_ Michael. He doesn’t remember slitting his throat, doesn’t remember stabbing him in the gut, doesn’t remember dropping him into the pre-made grave Castiel had dug the day before.

What he does remember is Castiel holding his hand over the knife handle to angle it properly, so he gets the best slice from ear to ear across the throat. He remembers Castiel carding fingers through his hair as he straddled Michael’s body and drove the knife into his gut over and over again. He remembers kicking Michael into the hole in the ground and turning to see Castiel wearing the prettiest, most genuine smile he’s ever seen. 

“Cas,” Dean breathes, his breath fogging in the air. 

Castiel transforms from a robot into beauty. 

The kiss is messy. Dean’s nearly positive Castiel has never kissed anyone in his life, because he’s all teeth and snarling and too-hard grip. They stumble until Castiel has Dean pinned to a tree, their bodies heating up in the cold night, steam practically rolling off of them as they tear at each other’s clothes. Really they can’t get much done, and between clashing teeth Castiel reminds Dean that they can’t leave DNA evidence, but they still _need_ , they still want and desire and wow. 

That weight in Dean’s gut? That heaviness that worsened with every encounter with Michael, that awful, terrible anvil that got more and more foreboding with every incident of “bad luck” Dean encountered?

Vanished.

He’s light as a fucking feather. 

Castiel takes him past the stars and shoots through the solar system. His grip on his cock is too tight, he bites Dean’s neck hard enough to break the skin all so he can lick it back up. Dean returns everything tenfold, brimming with experience but impatient with the must-have. And oh, he knew he’d had a crush on his stupid asshole roommate and really, this should really fucking concern him, but honestly he’s just too fucking turned on to care. Bring on the dead bodies. Let Castiel drag him into an alibi. Let all the rude bitches in the fucking world burn to the Goddamn ground if it means Dean can peek past the mask to get at the real Castiel Novak beneath. He’s so fucking strong and hot and weird but then, what does this all say about Dean? 

“Cas-” 

Castiel _bites_ his throat, the flesh mottling a morbid purple, teeth marks indenting the skin around the suck point. Dean’s fucking lost, anyway. 

Hands wrapped around each other’s cocks, they hump until they can’t anymore, until Dean is sure they’re gonna fall to the ground because they can’t stay upright. Orgasm sweeps Castiel first, and he has the mind to grab the hem of Dean’s shirt, which is stretcher than his button-down, to catch his release. The blatant disregard for his clothes has Dean rocketing over the edge, as ridiculous as it is, and soon his shirt is damp and sticky with both their cum, their foreheads pressed together as they come down from the high. 

Castiel pulls away first, always able to collect himself better and faster. Dean feels like a slug. He looks at the grave, unable to see Michael’s body from this angle, and instead of feeling disgusted with himself, he lets out another hysterical giggle, wiping a hand over his face. 

“What the fuck have you done to me?” 

Like a fucking robot, per usual, Castiel picks up one of the shovels and sends an arched brow toward Dean. There’s the tiniest flicker of amusement in his eyes as he says, “Opened your mind.” 

Chewing his lip, Dean moves to pick up the other shovel. “How do you know I won’t turn you in?” 

“Because you’ll go down too,” Castiel points out the obvious. Then, allowing true amusement to shine on his hot fucking face, he says, “And I think you’ll be good at this.” 

“Good at being a murderer?” Dean snorts.

“After three you’ll graduate to serial killer,” the other says conversationally. The sound of dirt falling onto the tarp nearly drowns their conversation.

Dean’s gut dips a little bit. This time out of frenzied, aroused curiosity, not dread. “How many people have you killed?” 

“Enough that I’m looking for houses in a different state.” 

Quieting, Dean plants his shovel and rests his elbow on the handle, narrowing his eyes at Castiel. “Alone?” 

The man just shrugs.

Dean hums conversationally, shrugging as he starts shoveling once more. “Sounds to me like you’ll need to keep having alibis at the ready.” 

He doesn’t imagine the smirk on Castiel’s lips as they bury Michael’s bloody, worthless body. 

“That sounds about right.”

Dean smiles to himself. He still feels light as a feather. With Castiel’s feet on the ground, he knows he won’t float away. 

“When’s our lease up?”

**Notes for the Chapter:**

> FOR A LIMITED TIME ONLY FOR THE SERIES FINALE I WILL BE ON [TWITTER](https://twitter.com/deansdayzdukes)  
> 🎉  
> TWITTER ACCOUNT WILL BE ACTIVATED ON 11/16 AND DEACTIVATED ON 11/23  
> Let's get through this together, babes! ❤


End file.
